Data Manipulation: The String Concatenator Node

Data Manipulation: The String Concatenator Node

The StringConcatenator node is a flexible utility for combining multiple strings into a single text block. It takes a list of strings, resolves any variables within them, and joins them together using a specified delimiter. This is perfect for assembling complex prompts, formatting reports, or creating structured text from various data points within the workflow. If designated as a responder, this node can also stream its output just like a StaticResponse node.

How It Works

1. Configuration Loading: The processor loads the strings list and the delimiter string from the node's configuration.
2. Variable Substitution: The system iterates through every item in the strings list and processes it with the WorkflowVariableManager, substituting all placeholders with their runtime values.
3. Concatenation: The resolved strings are joined into a single string, with the delimiter placed between each element.
4. Output Handling:
   • If returnToUser is false, the complete, concatenated string is captured internally as a variable (e.g., {agent3Output}).
   • If returnToUser is true and the request is for a streaming response, the node yields the final string to the client word-by-word, simulating an LLM stream.
   • If returnToUser is true and the request is for a non-streaming response, the complete string is returned to the user in a single block.
   • Even if returnToUser is undefined or false, if this node is the final node in a workflow it will appropriately respond to the user in streaming or non-streaming.

NOTE: Do not use returnToUser unless you have a specific need. Leave it false, or undefined. This is a breakout property and if used in an inappropriate location in the workflow can cause unexpected and undesirable results.

Properties

Variable Usage

Each individual string item within the strings list supports all available workflow variables. This allows you to mix static text with dynamic data from agent outputs, date variables, and more.

Full Syntax Example

This example assembles a multi-line user profile by combining custom workflow variables ({user_name}) with the output from a previous node ({agent1Output}) and a date variable. The \n delimiter ensures each item is on a new line.

{
  "title": "Assemble User Profile Block",
  "type": "StringConcatenator",
  "strings": [
    "--- User Profile ---",
    "Name: {user_name}",
    "Key Trait: {agent1Output}",
    "Report Generated: {todays_date_pretty}"
  ],
  "delimiter": "\n",
  "returnToUser": false
}